1. Field of the Invention
The present invention relates to an image printing system, image printing apparatus, and image printing method which can be suitably applied to a system designed to make a plurality of copying machines, multifunction apparatuses, printers, or the like, each having an electrophotographic image printing function, share and concurrently process an image printing job for outputting a plurality of prints, copies, or the like.
2. Description of the Prior Art
A conventional image printing system is formed by interactively connecting an image printing apparatus which receives image printing conditions and image information and serves as a master machine to an image printing apparatus which serves as a sub-machine to which the image printing conditions and image information are transferred from the master machine (e.g., pp. 2-3, and FIG. 3 in Japanese Unexamined Patent Publication No. 2002-127560).
In such an image printing system, when, for example, the master machine and the sub-machine share and concurrently process a printing job for outputting a plurality of prints, the master machine has a function of allowing selection of a proof mode of printing a single print as a proof output to check an output state by using the master machine.
When, for example, receiving an instruction to share a printing job with the sub-machine to concurrently process the job, and printing conditions and image information for the execution of the printing job, the master machine starts printing processing accompanying proof operation like that shown in the flow chart of FIG. 1.
Upon receiving printing conditions and image information, the master machine checks first, in accordance with the printing conditions, in step S111 in FIG. 1 whether or not printing operation is to be started in the proof mode. If printing operation is to be started in the proof mode (YES), the printing conditions are stored as job setting information in the storage area of the master machine in step S112.
Likewise, in step S113, proof execution information is recorded on the job status information stored in the storage area of the master machine. Lastly, in step S114, the output state of the master machine under the printing conditions stored in the storage area of the master machine is checked by executing proof output operation as check printing operation.
If printing operation is not to be started in the proof mode (NO in step S111), the flow advances to step S121 to check whether an instruction to execute proof output operation has been issued by checking whether proof execution information is recorded on the job status information stored in the storage area of the master machine. If no proof output operation is to be executed (NO), the flow advances to step S130 to transfer the printing conditions and image information to the sub-machine and execute final printing operation in order to output the set number of prints while sharing the printing operation with the sub-machine. Assume that proof output operation has already been executed (YES in step S121) and it is determined in step S122 that the printing conditions stored as job setting information in the storage area of the master machine differ from the printing conditions set as the current job setting information (YES). In this case, since printing conditions have already been set again, the flow advances to step S130 to transfer the printing conditions recorded as the current job setting information and the image information to the sub-machine and execute final printing operation.
If the job setting information stored in the storage area of the master machine does not differ from the current job setting information (NO in step S122), since the output state of a print obtained by proof output operation is good, the output print count is incremented by one in step S123. In step S124, the output print count is compared with the set print count. If the output print count is equal to the set print count (YES), since this printing job is complete, the flow advances to step S125 to terminate the printing job. If the output print count differs from the set print count (NO), the flow advances to step S130 to transfer the printing conditions and image information to the sub-machine and output the remaining number of prints concurrently with the sub-machine.
The following problems arise in the conventional image printing system.
1. Only the master machine can execute proof output operation in the proof mode, and the sub-machine outputs prints in accordance with the printing conditions and image information transferred from the master machine. If, therefore, the master machine and sub-machine differ in their mechanical characteristics or maintenance states, prints obtained by the master machine and that obtained by the sub-machine may differ in their output states. Even such differences are small, they cannot be allowed in a case wherein it is required to output a large amount of high-quality prints at high speed as in the POD (Print on Demand) market.
2. Since the output state of the sub-machine cannot be checked and printing conditions cannot be changed by the sub-machine, the output state of the sub-machine cannot be adjusted to match the output state of the master machine. For this reason, when it is required to output high-quality prints like those described above, it is difficult to concurrently process a printing job by using both the master machine and the sub-machine, resulting in a deterioration in the processing efficiency of the overall image printing system.